JP2001024943A - Image pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image pickup device equipped with a smear correcting means for preventing the occurrence of unnatural picture quality degradation such as resulting a breakdown with smear correction. SOLUTION: This image pickup device is provided with a CCD imaging device 5, a smear detecting part 8-1 for generating a smear removal reference signal by detecting a smear component while using the output of a vertical OB pixel from this imaging device 5, a smear correcting part 8-2 for correcting an effective image signal as an imaging device output during an effective signal output period on the basis of the smear removal reference signal generated by this smear detecting part 8-1 and a system controller 12 for changing the contents of correction in the smear correcting part corresponding to the level of the effective image signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup apparatus, and more particularly to an image pickup apparatus having a pseudo signal correction function.

[0002]

2. Description of the Related Art Conventionally, in a solid-state imaging device using a CCD image sensor, a phenomenon peculiar to the CCD image sensor is as follows.
There is a problem of image quality deterioration due to a smear phenomenon that occurs when intense light enters. In other words, this phenomenon is due to the fact that the charge that has not been trapped in the original charge storage region crosses the potential barrier and leaks into the vertical transfer path. For example, in the case of a spotlight, vertical streaks extend above and below it.For example, in the case of a subject such as a landscape including the sky, in which a high-brightness portion extends in the horizontal direction, the entire screen has a flare-white A digitized image is obtained.

[0003] As a method of correcting this phenomenon, attention is paid to the fact that smears occur at substantially the same level in the vertical direction from the principle of generation, and the vertical OB (optical black) which is a light-shielded accumulation pixel area outside the effective pixel area is focused on. : Optical black)
A method of using the output level of a pixel as a smear removal reference signal and subtracting it from the pixel output signal of the effective screen is disclosed in, for example, Japanese Patent Application Laid-Open No. 7-67038 and is well known.

[0004]

However, if the smear correction is simply performed using the above-described conventional technique, the smear component is large because the output range of an image sensor used in a real camera is limited. In such a case, there is a problem that the image quality is deteriorated by the correction. This will be described using a specific example. Considering a state in which vertical streak-like smear due to a strong spot light is generated at a level (100%) reaching the saturation level of the image sensor, a portion where no smear exists is considered. Although the image sensor output signal is output as it is even after smear correction,
In the smear portion, the output of the device remains at 100% due to the saturation of the image pickup device, so that the output after smear correction (device output-smear component) becomes zero. Therefore, a vertical black streak is generated. Alternatively, if the spot light portion itself is viewed as a subject at this time, this portion also has an output of 0. The phenomenon of black streaks extending vertically and objects that are supposed to be very bright are blackened,
It produces an extremely strange image, and even if a normal subject with a small smear level can be imaged with higher image quality than before, image quality degradation that is unacceptable for an imaging device targeting various subject scenes (Failed image), and therefore, the conventional smear correction method has a problem that it is difficult to adopt it.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem in the conventional smear correction method, and at least an imaging apparatus capable of performing effective smear correction without causing unnatural image quality deterioration at least causing failure. The purpose is to provide. The purpose of each claim is as follows.

That is, an object of the present invention is to provide an image pickup apparatus provided with a smear correction means capable of suppressing the generation of a new false signal due to signal saturation or the like. An object of the invention according to claim 2 is to provide an image pickup apparatus provided with a smear correction unit capable of suppressing the generation of a false signal due to a so-called value jump (discontinuity) with respect to a change in an image signal. And It is an object of the invention according to claim 3 to provide an image pickup apparatus provided with a smear correction unit that prevents a problem such as generation of so-called black streaks due to correction calculation. A fourth object of the present invention is to provide an imaging apparatus including a smear correction unit capable of obtaining a more effective correction characteristic according to a smear occurrence level. An object of the invention according to claim 5 is to provide an imaging apparatus including a smear correction unit capable of suppressing the generation of a false signal due to so-called value jump (discontinuity) with respect to a change in a smear component. And An object of the invention according to claim 6 is to provide an imaging apparatus including a smear correction unit configured to suppress generation of an unnatural false signal. It is another object of the present invention to provide an imaging apparatus including a smear correction unit that prevents an output level difference (step) caused by signal saturation. An object of the invention according to claim 8 is to provide an imaging apparatus including a smear correction unit configured to prevent the output level from being lowered due to the correction and the image from becoming dark.

[0007]

According to a first aspect of the present invention, there is provided an image pickup device comprising: an image pickup device; and a smear component of the image pickup device based on an output of the image pickup device corresponding to a vertical blanking period. And a smear correction unit for correcting an effective image signal output from the image sensor during an effective signal output period based on the smear component detected by the smear detection unit, according to a level of the effective image signal. The image pickup apparatus is constituted by the correction processing control means for changing the content of the correction processing in the smear correction means.

[0008] In the imaging apparatus configured as described above,
Since the content of the correction processing in the smear correction unit is changed according to the level of the effective image signal, it is possible to suppress the occurrence of a new false signal due to signal saturation or the like.

According to a second aspect of the present invention, in the image pickup apparatus according to the first aspect, the change in the correction processing content by the correction processing control means is performed by correcting the change in the level of the effective image signal by the smear correction means. It is characterized in that the subsequent output value changes continuously. With such a configuration, the output value after correction changes continuously with the change in the level of the effective image signal. It is possible to suppress the generation of the spurious signal due to this.

According to a third aspect of the present invention, in the imaging apparatus according to the first or second aspect, the change of the correction processing content by the correction processing control means is such that at least a level of the effective image signal reaches a predetermined signal saturation level. In this case, the smear correction is set to no correction in the case where the error has occurred. With this configuration, when the level of the effective image signal has reached the predetermined signal saturation level, no correction is performed, so that a problem such as generation of so-called black stripes due to correction calculation does not occur.

According to a fourth aspect of the present invention, there is provided an image sensor, a smear detecting means for detecting a smear component of the image sensor based on an output of the image sensor corresponding to a vertical blanking period, and a detecting means for detecting the smear. Smear correction means for correcting an effective image signal output from the image sensor during an effective signal output period based on the obtained smear component, and correction processing in the smear correction means according to the level of the smear component detected by the smear detection means And the correction processing control means for changing the image data.

[0012] In the imaging apparatus configured as described above,
Since the contents of the correction processing in the smear correction means are changed according to the level of the smear component, more effective correction characteristics according to the smear occurrence level can be obtained.

According to a fifth aspect of the present invention, in the imaging apparatus according to the fourth aspect, the change in the correction processing content by the correction processing control means is performed after the change in the level of the smear component is corrected by the smear correction means. Is to be changed continuously. In the imaging apparatus configured as described above, the output value after correction is continuously changed with respect to the change in the level of the smear component. Therefore, the so-called value jump (discontinuous) is performed with respect to the change in the smear component. It is possible to suppress the generation of a false signal due to the above.

According to a sixth aspect of the present invention, in the image pickup apparatus according to the fourth or fifth aspect, the change of the correction processing content by the correction processing control means is performed when the level of the smear component is equal to or more than a predetermined value. It is characterized by no correction. In the imaging device configured as described above, no correction is performed when the level of the smear component is equal to or more than the predetermined value. Therefore, in a situation where the smear component occupies all or most of the image signal, it is dared. Since no correction is performed, generation of an unnatural false signal can be suppressed.

According to a seventh aspect of the present invention, there is provided an image pickup device, and a smear detecting means for detecting a smear component of the image pickup device based on an output of the image pickup device corresponding to a vertical blanking period.
And a smear correction unit for correcting an effective image signal output from the image sensor during an effective signal output period based on the smear component detected by the smear detection unit, wherein the smear component is different even if the value of the detected smear component is different. The imaging apparatus is configured so that the maximum output level of the correction means is kept equal.

In the imaging apparatus having the above-described structure,
Even if the value of the smear component is different, the maximum output level of the smear correction means is kept equal, so that the occurrence of an output level difference (step) due to signal saturation can be prevented.

According to an eighth aspect of the present invention, in the imaging apparatus according to any one of the first to seventh aspects, the maximum level of the signal is kept equal before and after the correction by the smear correction means. It is characterized by having. With this configuration, the maximum level of the signal is kept equal before and after the correction by the smear correction unit, so that it is possible to prevent the output level from decreasing due to the correction and the image from becoming dark.

[0018]

Next, an embodiment will be described. FIG. 1 is a block diagram showing a digital video camera of a main embodiment of an imaging apparatus according to the present invention. In FIG. 1, 1 is a lens system, 2 is a lens driving mechanism, 3 is an exposure control mechanism, 4 is a filter system, 5 is a CCD image sensor, 6 is a CCD driver, 7 is a pre-processing circuit including an A / D converter, 8 Is a digital process circuit that includes a memory as hardware and performs all digital process processing. 9 is a recording unit (VTR block), 10 is a video tape, 11 is an LCD image display system, 12 is a system controller including a microcomputer as a main configuration, 13 is an operation switch system, 14 is an operation display system including a display LCD, 15 Is a lens driver, 16 is an exposure control driver,
17 is an EEPROM.

In the digital video camera constructed as described above, the system controller 12 performs overall control, and includes an exposure control mechanism 3 as an iris diaphragm (iris) and a CCD driver 6 by a CCD driver 6.
By controlling the driving of the image pickup device 5, exposure (charge accumulation) and signal readout are performed at a predetermined moving image rate, and the signals are temporarily stored in the digital process circuit 8 via the preprocess circuit 7, and are stored therein. After performing various signal processing, the signal is sent to the recording unit 9 and recorded on the video tape 10. The digital process circuit 8 for performing the above-described various signal processing includes a vertical OB which is a main part of the present invention.
A smear detection unit 8-1 for detecting the output level of the pixel, and a smear correction unit 8--1 using the output level information of the vertical OB pixel.
2 is included. Of course, all of these processes are performed at a speed sufficient to perform recording at the predetermined moving image rate.
This is so-called real-time processing. The system controller 12 controls the content of the smear correction process performed by the smear correction unit 8-2 based on the detection of the smear component of the image sensor.

Next, camera control by the system controller 12 will be described focusing on processing directly related to smear detection and smear correction of the present invention. First, an image pickup output signal corresponding to one screen, which is obtained by sequentially reading out signal charges of the CCD image pickup element 5 generated by the exposure in the above operation, is stored in a predetermined memory area of the digital process circuit 8 via the pre-process circuit 7. Detection unit 8-1
, A smear component is detected using the output of the vertical OB pixel, and a smear removal reference signal is calculated. In the calculation, the sum of each pixel having the same horizontal address among the data of the OB pixels on a plurality of lines is calculated as necessary and divided by the number of pixels, as in the case of the prior art disclosed in the above-mentioned publication. Get. The smear removal reference signal is an image signal for one line.
The average value obtained by the above calculation is used as the value of the pixel signal. The smear removal reference signal obtained in this way is represented by Sm
(i). Here, i is a horizontal address, and j described later is a vertical address.

Then, the smear correction unit 8-2 performs a correction process on the imaging output signal Sig (i, j) of the effective image area using the smear removal reference signal. The smear correction processing of the present invention is characterized in that different processing is performed in accordance with the imaging output signal and the level of smear at this time. The saturation level of the image sensor (or a signal processing system receiving the output) is Sat, and the predetermined comparison levels are R1 and R2 (0 <R1 <
R2 <Sat), assuming that the output after smear correction is Sout (i, j) (of course, 0 ≦ Sm (i) ≦ Sig (i, j) ≦ Sat), a specific smear in the present embodiment. The correction signal processing is performed corresponding to the following cases (1) to (3). (1) When 0 ≦ Sm (i) ≦ R1 Sout (i, j) = S1 (i, j) {Sig (i, j) −Sm (i)} × S
at / {Sat−Sm (i)} (2) When R1 ≦ Sm (i) ≦ R2 Sout (i, j) = S2 (i, j) ≡Ofs (i) + ｛Sig (i, j) − S
m (i)｝ × {Sat-Ofs (i)} / {Sat-Sm (i)} where Ofs (i) ≡ ｛Sm (i) -R1｝ × R2 / (R2-R
1) (3) When R2 ≦ Sm (i) ≦ Sat Sout (i, j) = Sig (i, j)

As described in (1), (2) and (3) above, S
FIGS. 2A to 2D show input / output characteristics of the smear correction unit 8-2 when the cases are classified according to the value of m (i). 2A to 2D, the horizontal axis represents the input Sig (i, j).
The vertical axis is the output Sout (i, j). FIG. 2A shows the case of (1), and FIG. 2B shows the boundary (common) of (1) and (2).
The case, FIG. 2C is the case of FIG. 2B, and FIG.
Indicates a boundary (common) case between (2) and (3).

Here, in order to explain the specific meaning of the smear correction signal processing according to the present embodiment, a conventional processing method to be compared is shown in the following item (4). (4) Always Sout (i, j) = Sig (i, j) -Sm (i)

In the above description of the problem of the prior art, an example of a problem which is particularly easy to understand is shown. However, if the problem of the prior art is generalized, the problem is that the range of the output signal becomes small, that is, This means that the maximum value of the correction output Sout (i, j) is reduced by the smear level and becomes Sat-Sm (i). For this reason, in the extreme case, the above black streaks are generated. However, otherwise, "when a saturation occurs, that is, Sig (i, j) = Sat", "a smear exists, that is, Sm (i )> 0 ", gray to black streaks are generated according to the smear level, resulting in an unnatural strange image which is extremely unnatural as compared to white streaks when no correction is made. become. These modes are shown in graphs in FIGS. 3A and 3B. FIG. 3A is a diagram showing input / output characteristics in the case of no correction, and FIG.
The input / output characteristics of the smear correction shown in the above section (4) are shown. From the characteristic of FIG. 3B, it can be seen that although only the original signal component is obtained, the maximum value is small.

On the other hand, in the embodiment according to the present invention, the cases (1), (2) and (3) are classified according to the value of the smear level Sm (i). In the equation representing (i, j), Sig (i, j) = S
By substituting at, the output Sout (i, j) = Sat is obtained. That is, "no correction is performed when the level of the imaging output signal has reached the saturation level". In this case, the portion becomes white output at the saturation level due to the influence of smear or the high luminance of the subject itself. However, since it is at least equivalent to the conventional uncorrected image, it is strange like the above-described conventional smear correction. No image is produced.

Here, apart from the above-described embodiment, if the output is not saturated, this is determined and detected, and the output of the conventional device having the characteristic shown in FIG. It is also possible to propose a modification in which the smear correction is selected, and if the signal is saturated, a non-correction of the characteristic shown in FIG. 3A is proposed as a modified example. Has a problem caused by discontinuous switching. For example, since smears are generated (superimposed) over a planarly distributed object and the whole of the object, considering the situation where the imaging output reaches near the saturation level, the output of the portion that has reached the saturation level is Since there is no correction, Sout (i, j) = Sat, and the portion that has not reached the saturation level just before is Sig
Since (i, j) −Sm (i) ≒ Sat−Sm (i), when the smear level is large, a level difference (step) that is originally impossible for the subject is generated, and a pseudo signal is generated. As one method for solving the step problem, which can be considered as a modification example, a maximum smear (Max [i]
Focusing on {Sm (i)}), all the effective pixel outputs are Sat−
It is effective to clip at Max [i] {Sm (i)}, but naturally the imaging range is reduced, and the entire screen is darkened to remove spot smear.

In the main embodiment described above, Sout (i, j) is a continuous function for both Sig (i, j) and Sm (i) so that this does not occur. The maximum output level of the smear correction unit is made to be equal regardless of the value of the smear component, and at the same time, the maximum level of the signal is kept equal before and after the correction. This is a very characteristic configuration, and therefore, does not cause the disadvantages of the above-described modified example.

That is, the conversion characteristics (input / output characteristics) corresponding to each case of the smear correction processing are shown in FIGS.
As shown in (D), in the case of (1), the input level is multiplied by a predetermined coefficient corresponding to the smear level to compensate for the shortage of the output range in the processing of the conventional case (4). S1 is such that the output also reaches Sat when is Sat
(i, j) is adopted. Comparing FIG. 2A with FIG. 3B, FIG. 2B shows that in FIG. 2A {in the case of (1)}, the lower the luminance, the more only the original signal components become. (Coincidence when the signal component = 0), and on the high luminance side, it approaches the uncorrected value shown in FIG. 3A (S).
ig (i, j) = Sat). When the level of occurrence of smear is relatively small, especially in a low-luminance subject, the expression S1 (i, j) is a compromise between the smear correction effect and the elimination of the above-mentioned conventional disadvantageous phenomena. Has been effectively balanced.

With only the characteristics of the equation S1 (i, j), Sm (i)
When becomes very close to Sat due to the increase of, the graph stands almost vertically, and approaches a characteristic that is discontinuous (has a value jump) with respect to Sig (i, j). Also, in such a case, since the effective range of the image sensor is scarcely left in the first place, it is meaningless to perform signal correction for many subjects and output it. It can be said that the adverse effect is greater than the effect of the correction. Considering this point, this equation S1
The characteristic of (i, j) is limited to the case of (1) where Sm (i) is equal to or smaller than a predetermined value (≦ R1), and the characteristic of (3) is large when Sm (i) is large (≧ R2). In this case, there is no correction and this 2
For the corresponding case (2), the offset term Ofs changes from 0 to R2 corresponding to the value of Sm (i) going from R1 to R2 so as to smoothly transition between the two cases. The equation S2 (i, j) having (i) is adopted.

As a whole, the generation of smear at a relatively low level is relatively close to the conventional smear correction (an output closer to the original subject signal is obtained in a low-luminance subject portion where smear is conspicuous). Defects caused by signal saturation caused by conventional correction are greatly reduced while having a high correction effect. The correction process is performed.

The output image signal Sout (i, j) subjected to the smear correction as described above is recorded on the video tape 10 or displayed on the LCD image display system 11 through various signal processings as appropriate. The image to be recorded or displayed is a high-quality image in which smear is effectively corrected and unnatural spurious signals are not generated.

Further, the present camera includes the above-mentioned various signal processing and has a conventionally known pixel defect compensating means. The output signal after smear correction corresponding to the effective pixel portion is stored in the EEPROM 17. This pixel defect compensation processing is performed based on the defective pixel address data. At this time, it is significant to perform the smear correction processing first and perform the defect compensation processing later. This is because the output signal of a different horizontal address is usually used for the defect compensation processing. Therefore, if the processing order is simply changed and the defect compensation processing is performed first, the smear correction processing is not performed correctly, and a new false signal is caused. This is because it is not preferable.

It should be noted that various embodiments other than the above-described main embodiment are conceivable. For example, in the above-described embodiment, the case using the smear correction processing divided into the cases (1), (2), and (3) has been described. As shown in the case, the expression S1 (i,
j) may be applied. In this case, as described above, Sig
Although the characteristic approaches a discontinuous (jumped value) characteristic with respect to (i, j), the occurrence of black streaks due to saturation as in the correction processing shown in the conventional case (4) does not occur. The image is not particularly unnatural even when compared to the white streak image in the case of completely no correction. Compared to the main embodiment, not only is the operation simplified, but also the characteristics are small, but it is excellent from the viewpoint of maximizing the use of the remaining range of the imaging device. It is a very attractive modification. Similarly, in the main embodiment, it is obvious that the one in which R2 = Sat is set, that is, the case using only the cases (1) and (2) can be a modification.

In the main embodiment, an output corresponding to a so-called vertical OB pixel is used for smear detection. However, this is an example, and there is no photoelectric conversion element (pixel storage unit) that actually corresponds. However, since smear detection can be similarly performed using the image sensor output corresponding to the vertical blanking period, it is obvious that the present invention can be implemented even by replacing with such a known configuration.

Further, in the above-described main embodiment, a moving image is mainly recorded. However, since signal processing is performed only for one frame image (intra-frame processing), the still image photographing is performed as it is. It is obvious that the present invention can be applied to a still image shooting mode additionally provided by the above-mentioned camera, or to another still image shooting mode mainly applied to a digital still camera, and to the preferred embodiments, respectively. Become. Needless to say, the above description is not intended to limit the scope of the present invention to intra-frame processing, and it is easy to apply the present invention to inter-frame processing.

Although several embodiments of the present invention and modifications thereof have been specifically described above, the present invention is not limited to these embodiments, and may take any form as long as described in the claims. It goes without saying that it is a gain.

[0037]

As described above with reference to the embodiments, according to the present invention, it is possible to form a high-quality image in which smear has been corrected and smear has been reduced, and an unnatural spurious signal does not occur. An imaging device that can be obtained can be realized. In particular, according to the first aspect of the present invention, since the content of the correction processing in the smear correction unit is changed according to the level of the effective image signal, generation of a new false signal due to signal saturation or the like is generated. Can be suppressed. According to the second aspect of the invention, the output value after correction is continuously changed with respect to a change in the level of the effective image signal. ) Can be suppressed. According to the third aspect of the present invention, when the level of the effective image signal has reached the predetermined signal saturation level, no correction is performed. No problems occur. Further, according to the invention according to claim 4, since the correction processing content of the smear correction means is changed according to the level of the smear component, more effective correction characteristics according to the smear occurrence level are obtained. Can be According to the fifth aspect of the invention, the output value after the correction is continuously changed with respect to the change in the level of the smear component. Therefore, the change in the smear component is caused by so-called value jump. It is possible to suppress the generation of a false signal. According to the invention of claim 6, no correction is performed when the level of the smear component is equal to or higher than a predetermined value, that is, correction is performed dare in a situation where the smear component occupies all or most of the image signal. Since it is configured so as not to occur, generation of an unnatural false signal can be suppressed.
Further, according to the invention according to claim 7, since the maximum output level of the smear correction means is kept equal even if the value of the smear component is different, the output level difference (step) caused by signal saturation. Does not occur. According to the eighth aspect of the present invention, since the maximum level of the signal is kept equal before and after the correction by the smear correction means, the output level is reduced due to the correction, and the image becomes dark. Can be suppressed.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a digital video camera according to an embodiment of an imaging apparatus according to the present invention.

FIG. 2 is a diagram showing input / output characteristics of a smear correction unit for explaining a mode of smear correction in the embodiment of the present invention shown in FIG. 1;

FIG. 3 is a diagram showing input / output characteristics of a conventional smear correction for comparing smear correction with input / output characteristics in the present embodiment shown in FIG. 2 and input / output characteristics when no correction is performed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lens system 2 Lens drive mechanism 3 Exposure control mechanism 4 Filter system 5 CCD image sensor 6 CCD driver 7 Pre-process circuit 8 Digital process circuit 8-1 Smear detection unit 8-2 Smear correction unit 9 Recording unit 10 Video tape 11 LCD image Display system 12 System controller 13 Operation switch system 14 Operation display system 15 Lens driver 16 Exposure control driver 17 EEPROM

Claims (8)

[Claims] An image sensor, a smear detecting means for detecting a smear component of the image sensor based on an output of the image sensor corresponding to a vertical blanking period, and a smear component detected by the smear detecting means. The image processing device includes a smear correction unit that corrects an effective image signal output from the image sensor during an effective signal output period, and a correction process control unit that changes correction processing performed by the smear correction unit according to the level of the effective image signal. An imaging device characterized in that: 2. The method according to claim 1, wherein the correction processing content is changed by the correction processing control means such that an output value after correction by the smear correction means changes continuously with a change in the level of the effective image signal. The imaging device according to claim 1, wherein: 3. The method according to claim 1, wherein the change of the correction processing content by the correction processing control means is such that the smear correction is not corrected at least when the level of the effective image signal has reached a predetermined signal saturation level. Claim 1 or 2
An imaging device according to claim 1. 4. An image sensor, a smear detecting means for detecting a smear component of the image sensor based on an output of the image sensor corresponding to a vertical blanking period, and a smear component detected by the smear detecting means. Smear correction means for correcting an effective image signal output from the image sensor during an effective signal output period, and correction processing control for changing correction processing contents in the smear correction means according to the level of a smear component detected by the smear detection means An imaging apparatus comprising: 5. The modification of the correction processing content by the correction processing control means is such that the output value after correction by the smear correction means changes continuously with a change in the level of the smear component. 5. The method according to claim 4, wherein
An imaging device according to claim 1. 6. The method according to claim 4, wherein the change of the correction processing content by the correction processing control means is such that the smear correction is not corrected when the level of the smear component is equal to or more than a predetermined value. An imaging device according to claim 1. 7. An image sensor, a smear detecting means for detecting a smear component of the image sensor based on an output of the image sensor corresponding to a vertical blanking period, and an effective value based on the smear component detected by the smear detecting means. A smear correction unit that corrects an effective image signal output from the image sensor during a signal output period, so that the maximum output level of the smear correction unit is kept equal even if the value of the detected smear component is different. An imaging device characterized by being configured. 8. The imaging apparatus according to claim 1, wherein a maximum level of the signal is kept equal before and after the correction by the smear correction unit.